main.c

Go to the documentation of this file.

 
#include "includes/CPU.h"
#include <avr/io.h>
#include <util/delay.h>
#include "includes/pinDefines.h"
#include "includes/scale16.h"
#include "includes/organ.h"
#include "includes/pre_defined_songs.h"
#include "includes/USART.h"
 
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
uint16_t currentNoteLength = Q;
 
const uint16_t notes[] = {G4, Gx4, A4, Ax4, B4, C5, Cx5,
                          D5, Dx5, E5, F5, Fx5, G5, Gx5,
                          A5, Ax5, B5, C6};
 
int main(void)
{
    /* Initialize buzzer pin as output */
    BUZZER_DDR |= (1 << BUZZER_PIN);
 
    /* Initialize USART serial communication (9600 baud, 8N1) */
    initUSART();
 
    /* Display welcome message and control instructions */
    printString("---Serial Organ---\r\n");
    printString("Controls: a-s-d-f-g-h-j-k-l-;-' for white keys\r\n");
    printString("          w-e-t-y-i-o-p for black keys\r\n");
    printString("          1 to play Twinkle Twinkle Little Star\r\n");
    printString("          2 to play Imperial March from Star Wars\r\n");
    printString("          '[' = short note (250ms), ']' = long note (500ms)\r\n");
    printString("Ready!\r\n");
 
    char receivedChar;      
    uint8_t isNote;         
    uint8_t i;              
    const uint8_t keys[] = {'a', 'w', 's', 'e', 'd', 'f', 't',
                            'g', 'y', 'h', 'j', 'i', 'k', 'o',
                            'l', 'p', ';', '\''};
 
    /* Main program loop - runs forever */
    while (1)
    {
        receivedChar = receiveByte();
 
        transmitByte(receivedChar);
 
        isNote = 0;
        for (i = 0; i < ARRAY_SIZE(keys); i++)
        {
            if (receivedChar == keys[i])
            {
                /* Play the corresponding note with current duration */
                playNote(notes[i], currentNoteLength);
                isNote = 1;
                break;  /* Exit loop once match is found */
            }
        }
 
        if (!isNote)
        {
            if (receivedChar == '[')
            {
                /* Set short note duration mode (250ms, faster tempo) */
                currentNoteLength = Q;
                printString("\r\nShort mode (250ms)\r\n");
            }
            else if (receivedChar == ']')
            {
                /* Set long note duration mode (500ms, slower tempo) */
                currentNoteLength = H;
                printString("\r\nLong mode (500ms)\r\n");
            }
            else if (receivedChar == '1')
            {
                /* Play Twinkle Twinkle Little Star (blocks for ~10-15 seconds) */
                play_twinkle_little_star();
                printString("\r\nPlaying Twinkle Twinkle Little Star\r\n");
            }
            else if (receivedChar == '2')
            {
                /* Play Imperial March from Star Wars (blocks for ~30 seconds) */
                printString("\r\nPlaying Imperial March from Star Wars\r\n");
                play_imperial_march();
                printString("\r\nImperial March finished!\r\n");
            }
            else
            {
                if (receivedChar != '\r' && receivedChar != '\n')
                {
                    /* Play silence for unassigned keys */
                    rest(currentNoteLength);
                }
                /* CR and LF are silently ignored (no rest, no echo effect) */
            }
        }
 
        _delay_ms(10);
    }
 
    /* Never reached in embedded systems - infinite loop above */
    return 0;
}